1. Field of the Invention
This invention relates to an assembled light-emitting diode that houses a light-emitting diode chip (hereafter referred to as an LED chip).
2. Discussion of the Background Art
Light-emitting diodes that contain a pair of leads and LED chips that are connected electrically to the leads are known conventionally and various improvements have been made for the purpose of improving their performance and manufacturing yields. Conventional examples of this type of light-emitting diode are described in Japanese Patent Nos. 2,982,553 and 2,922,977. The example described in the former document is shown in FIG. 1(a) of the figures of this application and the example described in the latter is shown in FIG. 1(b). These figures show the cross-sectional structure in the vicinity of the LED chip-mounting portion.
In the example shown in FIG. 1(a), an improvement is made for the purpose of preventing electrical short circuits between leads. As shown in FIG. 1(a), the LED chip 510 has a pair of electrodes 520 and 530 on its bottom surface and these electrodes are electrically connected by connecting means 525 and 535 such as solders to the pair of leads 560 and 570. The insulating material 595 is placed between the leads 560 and 570 for the purpose of preventing short circuits between them. This insulating material can also decide a relative position of the two leads 560 and 570.
The cup component 650, which comprises an insulator that is linked to the tip of the pair of leads 660 and 670, is shown in FIG. 1(b). The cup component 650 is placed so that it engages with the shoulders 661 and 671 that are formed in the leads 660 and 670. The reflecting surface 623 that is formed inclined to the inside surface of the apex of the cup component 650 is constructed so that it can collect the emitted light from the LED chip 610 and reflect it upwards.
According to the construction of the light-emitting diodes shown in these prior documents, the LED chips are connected to the leads 560 and 570; 660 and 670 in the vicinity of the tips of the leads 560 and 570; 660 and 670 at which the LED chips 510 and 610 are arranged, after which a resin mold is formed to protect them. In FIG. 1(b), the resin mold is shown as reference number 690. The resin material that is used for this resin mold usually has a high coefficient of thermal expansion. Consequently, in the process of forming the resin mold, relatively great thermal stress acts on the leads 560 and 570; 660 and 670. Thereby undesirable stress is applied to the LED chip itself and to the connecting component between the LED chip and the leads and can be a cause of breakage of the LED chip or a poor connection.